Helena Jernstrom, an oncologist at Lund University in southern Sweden, said that the effect is the result of a gene that about half of women possess, The Local reported.
"Drinking coffee can have a major effect on breast size," she said.
Jernstrom became interested in the subject because of research that has shown that large-breasted women are more likely to be diagnosed with breast cancer, while downing at least three cups of coffee a day reduces cancer risk. She decided to look for a correlation directly between drinking coffee and breast size and found one.
Her study tracked 270 women. Jernstrom's results were published in the British Journal of Cancer.
Scarlett Johansson steps out with fiance after pregnancy reveal
Senate Democrats to pull all-nighter on climate change